13-04-2010, 09:22 PM
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Abstract “
This paper compares the present available converter technologies and provides an assessment of the advantages / disadvantages offered by each technology. The latest advances in high power semiconductor devices have resulted in the introduction of new concepts for high power rectifier systems. A comparison of traditional technologies and future technologies is made. The increased use of modern IT technology will also be briefly reviewed
Presented By:
Tony Siebert
Anders Troedson
Stephan Ebner
INTRODUCTION
High power converters have nearly a hundred years of history. The use of rectifiers in industrial applications started with the electromechanical contact converter followed by the era of mercury converters. In various development stages, mercury converter technology remained until the late 1950â„¢s until the invention of the semiconductor component. The new age started with diode rectifier plants and already in 1960 the first diode rectifier above 100 kA was installed; ten years later the first thyristor plant of this rating was operational. Today, rectifier units of more than 150 kA are possible and rectifier plants with process currents more than 350 kA. The future in aluminum industry goes towards 500 kA. Use of a semiconductor element mainly depends on its capability to dissipate the semiconductor losses. Forced cooled heat sinks are used today, which are cooled by de-ionized water or air. For high power converters, water-cooling is standard. On the first glance, we may think that the high power converter technology is a simple and well-established technique. Even when the key system components are well known for a long time, the challenge of today is to install the most suitable and reliable system architecture into the plant environment. Per definition, a power converter transfers energy from one state to another - in our case it is the so-called AC / network side to the DC / process side. On both sides the converter has to meet electrical and various other requirements.
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http://www05.abbglobal/scot/scot232.nsf/...ersion.pdf
